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VFC-03 Configuration

VFC-03 Configuration

Introduction

In all parameter descriptions, references to the "local unit" refers to the unit to be configured (LOCAL NOE or REMOTE NODE). This selection is identified in the LOCAL/REMOTE NODE selection in the Base Unit Configuration section.

The configuration of voice cards let you specify the input and output voice levels and examine the resulting voice quality. The voice level settings affect the quality of audio that telephone users will hear during the normal operation of the FastPAD. Once you verify that all circuits are functioning properly and optimal voice quality is achieved, use the Configuration Worksheets in Appendix C to record the final configuration.

VFC-03 Configuration Screens

When a slot number (1-8) is selected in the Configure Menu and a VFC-03 is installed in the selected slot, this configuration screen is displayed:

Ex <n> <VFC-03> <VCA> Rate: 16K DTMF Detect: 30 sec Interface: LOOP

EX <n>

This parameter specifies the expansion channel being configured where: <n> = the expansion channel number (1-8).

VFC-03 <VCA>

This field identifies the VFC-03 voice/fax card type and the voice compression algorithm used. It can be VFC-03 ATC or VFC-03 ACELP. If VFC-03 ACELP is selected, the Rate field defines which (either 4.8 kbps or 8 kbps) ACELP algorithm is used.For ATC 8-16 kbps is the only choice for rate. The default value is ATC 8-16K.


Note You cannot select VFC-03 ACELP if a VFC-01 module is also installed in the unit being configured, OR select different ACELP algorithms (i.e., 4.8K or 8K) for multiple VFC-03 expansion modules installed in the same unit.
There is only one clocking mechanism in the FastPAD; selecting multiple rates is invalid.

Rate

If the VFC-03 ATC voice compression algorithm is selected, it can be set to a value in the range 8K to 16 kbps. The default value is 16 kbps. If the VFC-03 ACELP algorithm is selected, this field can be set to 4.8K or 8K.

* DTMF Detect

This parameter enables (ON), disables (OFF), for the regeneration of DTMF tones OR specifies a number of seconds (2 to 255) in which DTMF tones will be regenerated. When enabled (ON), the FastPAD detects and regenerates DTMF tones. When disabled (OFF), DTMF tones are passed transparently to the remote unit.When a value in the range 2 to 255 is specified, the FastPAD will regenerate DTMF tones for the configured number of seconds. The default value is 30 (regenerate DTMF tones for 30 seconds including call setup).

Interface

This parameter and the Port Type parameter described in the last VFC-03 configuration screen specifies the telephony interface that will be used by this channel. If the ATC 8-16K voice compression algorithm is selected, it can be set to one of the following: Loop Start, 4-Wire E&M, 2-Wire E&M, 4-Wire E&M TE (Timed E&M) or 2-Wire E&M TE (Timed E&M).

If the VFC-03 ACELP 4.8 or 8K voice compression algorithm is selected, it can be set to one of the following: Loop Start, 4-Wire E&M, 2-Wire E&M, 4-Wire E&M TE (Timed E&M) or 2-Wire E&M TE (Timed E&M), AC16A, or AC15C. Loop Start is the normal setting for FXS and FXO operating mode.

Loop Start and FXS operating mode provides characteristics similar to those of a central office. Loop Start and FXO operating mode provides characteristics similar to those of a standard telephone set.

The 4-Wire E&M selection the normal setting for a PBX E&M tie line interface that uses one pair of wires for the incoming voice signal and another pair of wires for the outgoing voice signal. The 2-Wire E&M selection is for an E&M tie line that uses a single pair of wires for both the incoming and outgoing voice signal.

Select AC15A or AC15C if you intend to select the AC15 port type in the Port Type field. The default value is Loop Start.

When you exit the Interface field, the next VFC-03 configuration screen is displayed:

Ex <n> <VFC-03> <VCA> Suppression: ** In: 0 db Out: 0 db

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

* Suppression

This parameter is used to specify the silence suppression level. The silence suppression level is specified by entering 1, 2, 3, 4, or 5 asterisk (*) characters.

  * = very low suppression
** = low suppression
*** = medium suppression
**** = high suppression
***** = very high suppression

A larger silence suppression level results in greater savings in composite bandwidth. This allows more data channels to operate simultaneously with voice channels. The default value is two asterisks (**).

In

This parameter specifies the local voice level into the voice port, measured in 1 dB increments. It can be set to a value in the range -22 to +7 dB. The value of this parameter adjusts the sensitivity of the local voice channel to the signal from the attached device. The purpose of this parameter is to match the voice channel dB level to the input signal.

A more negative setting produces a higher input gain (i.e., +7 produces the least input gain, -22 produces the highest input gain). If the In level is reduced (made more negative), the voice channel will be more sensitive to the input; this will also cause the voice output at the Remote to sound louder. The default value is 0.

Out

This parameter defines the local voice level out of the voice port. It can be set to a value in the range -22 to +7 dB. A more positive setting produces a higher volume (i.e., +7 produces the highest volume, -22 produces the lowest volume). The default value is 0 dB.

If a call is active and voice traffic is present on the selected channel, asterisk characters (*) will be displayed next to your entry as In and Out levels are specified. These asterisks indicate the actual voice levels into and out of the FastPAD as voice input and output levels are being specified. Typically, between 3 and 4 asterisks (*** or ****) will be displayed when the setting is correct.

Actual operating levels may vary considerably, depending on the type of voice circuit and connection interfacing the voice channel, the type and quality of telephone instruments used, and the speakers. Start with the default values shown, and adjust each level 1 or 2 dBs in either direction until the optimum voice quality is achieved.

Voice Level Considerations

The VFC-03 is capable of operating as an FXS, FXO, or E&M device and each device type has its own unique requirements for voice levels that will provide the highest quality voice. The perceived voice quality is also affected by the type of telephone handset being used, ambient noise conditions, and the characteristics of the speaker's voice.

Because so many variables affect voice quality, it is usually necessary to fine tune the voice levels beyond the recommended settings. For example, the recommended settings for FXS are -9 dB input and -13 dB output. The adjustment of input level determines the sensitivity of the voice channel to the incoming signal. With a setting of -9 dB, the voice channel expects a -9 dB input signal. If the actual input signal is -20 dB, it will be too weak and the resulting output at the remote will also be weak. Therefore, the input level setting must match the dB level of the actual incoming signal.

The output level is similar to a volume control and should be set to match the level expected by the attached device. A proper adjustment should provide a comfortable listening level with no distortion or overdriving of the signal.

Setting Voice Levels

The following steps describe how to adjust voice levels settings and the local and remote sites:


Step 1   Establish a connection with a person at the remote site.

Step 2   From the Configure menu, select the expansion channel number where you want to set voice levels (where the connection is established).

Step 3   Use the <Down Arrow> key to select the configuration screen where In and Out levels are set in this screen:

EX <n> VFC-03 ATC Suppression: ** In: -9 dB **** Out: -13 dB ****

Step 4   Set the Input level to -9 dB for an FXS connection, -13 dB for an FXO connection, or -15 dB for an E&M type connection.

Step 5   While speaking into the handset in a normal voice, observe the level indicators adjacent to the In field.The display should indicate an average of between three and four asterisks (*) next to the "In" caption at the bottom of the window.

Step 6   If the display shows more than four asterisks, it means the actual signal is stronger than the voice input level setting. When this is the case, reconfigure the channel to a less sensitive setting or to a higher (less negative) number (e.g., -7 dB for an FXS connection).

Step 7   If the voice sounds weak with missing syllables or the display shows less than three asterisks, it means the incoming signal is weaker than the configured setting. When this is the case, adjust the input level to a higher sensitivity setting—which means a lower (more negative) level (e.g., -11 dB for an FXS connection).

Step 8   Continue adjusting the level higher and lower in two dB increments, then one dB increments until the In level displays three and one-half asterisks.

Step 9   Instruct the person at the remote site to complete steps 1-8 for the input level (their local input level) at the remote unit.

When input levels have been adjusted to the appropriate values at both the local and remote sites, this procedure can be repeated for the local and remote output levels. The starting output level values are -13 dB for FXS, -9 dB for FXO, and -15 dB for E&M.

When adjusting the local output level, instruct the person at the remote site to speak in a normal voice while you observe the local Output level indicator. Between three and four asterisks should be displayed next to the Out caption when the voice is at a comfortable listening volume with no overdriving of the volume.

If necessary, adjust the local output level until three and one-half asterisks are displayed. Repeat the output adjustment for the remote unit by speaking in a normal voice as the remote person adjusts the remote output level (their local output level).

The new level settings take effect when saved to Active or Active and Saved in the Store To menu. When you exit the Out field, the next VFC-03 configuration screen is displayed:

EX <n> VFC-03 <VCA> Call Timer: 5 sec In Hunt Group: A Long Dial Prefix: #

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

Call Timer

This parameter specifies the amount of time the FastPAD should wait for a response to a Call Connect or Call Clear request. It can be set to a value in the range 1-30 seconds. The default value is 5 seconds.

When the FastPAD issues a Call Connector or Call Clear request, it will set a timer equal to the value specified here. If that timer expires with no response from the destination, the FastPAD will generate a busy tone.

* In Hunt Group

This parameter includes the channel in Hunt Group A or B, or excludes the channel from an Expansion Channel Hunt Group. The default value is A.

(A) indicates this channel belongs to Hunt Group A. (B) indicates this channel belongs to Hunt Group B. (No) excludes the channel from both hunt groups.

* Long Call Prefix

This parameter is used to specify a prefix character that is required preceding calls using the long call format. It can be set to a single digit 0-9, asterisk (*), or pound-sign (#). The default value is the pound sign (#).

When the user at an attached device (e.g., telephone or Fax machine) dials a long form number (i.e., not a speed dial number), it must be preceded by the prefix character specified in this field.

When you exit the Long Call Prefix field, the next VFC-03 configuration screen is displayed:

EX <n> VFC-03 <VCA> Auto Dial: NO

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

Auto Dial

This parameter enables (YES) or disables (No) the auto dial function. When this parameter is enabled (YES), the Number field will be added to the configuration screen. When enabled and the handset attached to this port is taken off-hook, the system will attempt to establish a connection to the configured Number. The default value is NO (disabled).

When Auto Dial is enabled, the auto dial number field (<auto#>) and Auto Poll fields will be added to the configurations screen:

EX <n> VFC-03 <VCA> Auto Dial: YES <auto#> Auto Poll: NO

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

<auto#>

When Auto Dial is enabled (YES) and the handset attached to this port is taken off-hook, the system will attempt to establish a connection to the auto dial number specified in this field. Enter a speed dial number that is defined in the Map configuration table. The number digits (2,3,or 4) that can be entered is linked to the number of Dial Digits specified in Map configuration that is associated with the speed dial number that you specify in this field. The default value is 0000.

Auto Poll

When Auto Dial is enabled, this field is used to enable (YES) or disable (NO) auto polling. When enabled, the system will periodically send a poll to the destination. If the poll is not acknowledged the system will busy out the channel. The default value is disabled (NO).

This parameter can be useful in situations where the destination is an emergency number that must always be available. If the destination does not answer the automatic poll, the busy-out condition will notify an attached PBX that the emergency call should be routed to another call routing device (e.g., ACD).

When Auto Poll is enabled, the next configuration screen is displayed:

EX <n> VFC-03 <VCA> Auto Poll Tmr: 10 s

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

Auto Poll Tmr

Enter a value in the range 5 to 30 specifying the frequency (in seconds) to send the automatic poll. The default value is 10.

When you exit the previous configuration screen, the next VFC-03 configuration screen is displayed in the following format:

EX <n> VFC-03 <VCA> FXO Timeout: 30 Link Down Busy: YES Port Type:

Where: <VCA> = ATC for the ATC 8-16K voice compression algorithm or ACELP for the ACELP 4.8K or ACELP 8K voice compression algorithm.

* FXO Timeout

The Local FXO timeout parameter defines the amount of time (1-99 seconds) that the local port connected to the PSTN will wait before an actual Fax transmission begin. If there is no Fax tone when this timer expires, the connection will be terminated. The default value is 30 seconds.

Link Down Busy

This parameter enables (YES)/disable (NO) automatic busy-out of channels when the link is down. When this parameter is enabled, the system will automatically busy-out channels when the composite link is down.

When disabled, channels remain on-hood when The link is down. If your applications is connected to a PBX that can route calls to an alternate source (e.g., an ACD) based on an "allbusy" condition, enable this parameter so that the PBX will recognize this condition and reroute the calls while the composite link is down. The default value is YES (enabled).

Port Type

This parameter and the Interface field described above select the telephony interface to be used by this channel. It can be set to one of the following: FXS, FXO, E&M or AC15. If 4-Wire is selected in the Interface field, this field must be set to E&M. If E&M is selected, you must also set Switch 2 on the VFC-03 to select an E&M type (I,II,III,IV, or V).The AC15 selection is only valid for VFC-03 ACELP. The default value is FXO.

This is the last VFC-03 configuration screen. You may use the <Up Arrow> and <Down Arrow> buttons to review your entries. Press the <Enter> button to display the Store To screen described below.

The Store To Menu


Note When the FastPAD is connected to a Rel. 7.2 or later IPX, use the front panel ONLY for System (Map) or expansion card parameters identified with an *.

To reach this menu, the IPX must have unlocked the FastPAD front panel. When a STORE is performed, there is a possibility that the IPX will adjust the stored values to conform to IPX network parameters. This adjustment occurs when "lockfp" is executed on the IPX or when the IPX connects to the FastPAD the next time.

When you press the <Enter> key in any of the configuration screens, the system will display the Store To menu in the following format:

Store to: ACTIVE & SAVED ACTIVE ONLY SAVED ONLY
ACTIVE and SAVED

This selection will store the configuration parameters in EEPROM and use them immediately.

ACTIVE ONLY

This selection will allow you to use the new configuration parameters immediately, but they will not be stored permanently. The changes are stored in RAM but not in non-volatile EEPROM.

SAVED ONLY

This selection will store the configuration parameters in EEPROM, but they will not be used until the next power-on reset or cold boot start.

You may also press the <Esc> key in this or any other configuration screen to exit the configuration function without changing anything.When you press the <Enter> key in the Store To menu, the system will confirm your selection with a screen in the following format:

Saving Configuration


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Posted: Thu Jan 25 13:32:43 PST 2001
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